In the manufacture of chandelier frameworks, assemblies made of arms radiating from a central region are required. Such arms may radiate from the center unsupported at the outer end, thus forming a rimless wheel, or may be joined at the outer end to a ring, thus forming a wheel. In other applications, outwardly radiating spokes may return to a second center at a different level, thus forming a cage. In connection with chandelier frameworks, the arms are customarily attached to a central location such as, for example, a round disk by various means including welding or soldering the arms directly to the center disk. A disadvantage of this method is the impossibility of removing the arms when repair is necessary. Other disadvantages include the high cost of soldering or welding spokes due to the requirement of skilled labor, the need for accurate jigs, and the like. Arms have also been held to such central disks by soldering or welding screws onto an end of each of the arms and then fastening the arms to the disk by passing these screws through holes in the disk. The screws are then secured by lock nuts. Disadvantages of this method of attachment include the lack of structural strength, the high cost of soldering or welding the screws onto the spokes and the requisite skilled labor for such operations, the need for accurate jigs, the sideways motion and misalignment of the arms in the case of loosened nuts, and the like.
Arms have also been riveted, eyeletted, or flanged to a disk. Again, there are many disadvantages including the lack of structural strength, attachment of arms to the disk with external fasteners that greatly reduce the weight-supporting strength of the arms, sideways motion of the arm when the rivet, eyelet or flange loosens, and the like. Furthermore, chandelier framework assemblies cannot be effectively manufactured from plastic or other modern synthetic materials according to any of the foregoing assembly methods.
When tubular arms are attached to disks, a complex procedure typically has been followed. First the tubing is rounded, using a cylindrical rotating pin and a lathe or drill press. Female threads then are cut into the rounded ends of the tubing and then a variety of means may be used to attach the threaded end of the tubing to the disks. Disadvantages abound. If a threaded tubing is attached to a disk by means of a lock nut and secured by a lock washer, the tubing has to be accurately oriented. The screwed connection is subject to various failures such as the stripping of the thread in the process of tightening it or the loosening of the lock nut as a result of handling or vibration, resulting in disorientation of the arm and, possibly, separation of the arm from the disk. Costly machining operations such as beading and threading and the lengthy procedure of attaching a beaded and threaded arm to a disk are further disadvantages typical of prior art methods.